Security telephone



FIG. 1 is a top plan view of a security telephone showing our new design;

FIG. 2 is a front elevation thereof;

FIG. 3 is a left side elevation thereof;

FIG. 4 is a right side elevation thereof;

FIG. 5 is a rear elevation thereof; and

FIG. 6 is a top front perspective view with the handset removed for clarity of illustration. 

The ornamental design for a security telephone, substantially as shown and described. 